<template>
    <div>
        <h1>计数器</h1>
        <h3>{{num}}</h3>
        <button @click="increment_Async">+</button>
    </div>
</template>

<script>
import {createNamespacedHelpers} from 'vuex'
const {mapState,mapActions}=createNamespacedHelpers('b')
export default {
  computed:{
    ...mapState(['num'])
  },
  methods:{
    ...mapActions(['increment_Async'])
  }
}
</script>

<style>

</style>